The objective of this Competitive Continuation (Type 2) application is to request additional funding to complete an ongoing NIH-sponsored Phase III clinical trial in Pune, India entitled "Prevention of Mother-to-Infant HIV Transmission in India", which was initiated 16 August 2002. This study is a randomized, 2-arm, open-labeled trial among HIV-infected mothers and their breast-fed infants designed to compare the safety and efficacy of standard maternal/infant single dose nevirapine (NVP) (Arm 1) to the single dose NVP regimen plus low-dose daily infant NVP for 6 weeks post-partum (Arm 2). The primary outcome of this trial is the comparison of infant HIV infection rates at 6 months post-partum. This study also has secondary objectives, including the measurement of maternal NVP drug resistance at 9 months postpartum, as well as the measurement of mortality and morbidity rates among participating mothers and their infants. Between 16 August 2002 and 31 July 2004, more than 20,800 consenting mothers have been HIV screened and 408 eligible mothers have been enrolled in the clinical trial. The NIAID DSMB for this clinical trial recommended the merging of the primary endpoint data from this trial in India, with data from similar trial sites in Ethiopia and Uganda. This recommendation was facilitated by the consistency in trial designs, study interventions, eligibility criteria, data management procedures and study procedures for all three sites. The total sample size for this new merged analysis is 1964, which will include data from 730 nfants from our trial site in India.